Why do people use telephones?
Very simply, to communicate when the distance between them is too great to speak face to face. But sadly, on more than one occasion, I have observed two dummies, while side by side, communicating with each other on cellfones !!! I guess they thought it was "cute," and their parents must have had more money than they or their kids had brains. It's an extremely useful and quick means of communication. Before the telephone was invented (and became widespread) people were dependent on mail services for communication over distance. Even if the mail service was efficient, just imagine the time for a short postal message to travel by surface from, say, a small place in Maine to another small place in, say, the Mississippi Delta!